Compressor

ABSTRACT

A compressor having a housing and an eccentrically mounted rotor in the housing. A plurality of pistons reciprocate in the rotor and bear against the housing. Passages in the pistons allow gas to flow underneath the pistons when the pistons are in the extended position, and the gas is compressed in the cylinders as the pistons move inwardly and expelled through a port at the inner end of each cylinder.

I Umted States Patent [111 4 [72] Inventor Meyer P. White 1,614,4811/1927 McMullen 230/177 157 Clark Road, Brookline, Mass. 02146 1,843.3382/1932 Replogle 230/177 [21] Appi. No. 778,989 2,386,459 10/1945Hautzenroeder,.. 103/161 [22] Filed Nov. 26,1968 2,642,804 6/1953 Bowers103/174 1 nled June 2,19 FOREIGN PATENTS 831,039 2/1952 Germany 103/162904,897 2/1954 Germany 103/161 [54] COMPRESSOR 2 Claims 6 Drawing 883Pnmary ExammerW|11|am L. Freeh AnorneyWolf, Greenfield & Sacks [52]U.S.CI 91/498 [51] Int. Cl. F04b l/l0 0 ABSTRACT; A compressor a housingand an ec ent i- 123/44 1 91/205; 92/58 ca11y mounted rotor in thehousing. A plurality of pistons reciprocate in the rotor and bearagainst the housing. Passages [56] Rem-cum Chad in the pistons allow gasto flow underneath the pistons when UNITED STATES PATENTS the pistonsare in the extended position, and the gas is com 935,655 10/ 1909 Haire230/177 pressed in the cylinders as the pistons move inwardly and ex-1,516,948 1 H1924 Benedix 91/205 pelled through a port at the inner endof each cylinder.

PATENTED JUN22 IQYI SHEEI 1 OF 2 FIG.

INVENTOR MEYER P. WHITE ATTORNEYS PATENTEDJUNZZIQYI 3585904 INVENTORMEYER P. WHITE ATTORNEYS COMPRESSOR This invention relates to a new andimproved compressor. One important object of this invention is toprovide a relatively small compressor capable of generating higherpressures at greater volumes than units of comparable size and cost nowavailable. At the present time compressors are generally of twovarieties, namely, reciprocating pump-type units and vane-type pumps.Reciprocating pump-type compressors usually require a two stageoperation to generate pressures in the range of 100 p.s.i., while thevane-type units now available are incapable of delivering pressures ofthat magnitude.

Another important object of this invention is to provide a compressorhaving a plurality of reciprocating pistons to achieve greatercompressor capacity.

Another important object of this invention is to provide a compressorwhich is free from leakage problems commonly encountered in rotarypumps.

Yet another important object of this invention is to provide acompressor of high rated capacity, which is inexpensive to manufacture.

Yet another important object of this invention is to provide acompressor requiring no lubrication and which compresses gaseousmaterials without introducing any oil or other lubricant into thecompressed gas.

To accomplish these and other objects, the compressor of this inventionincludes a housing with an eccentrically mounted rotor. A number ofpistons are reciprocally movable in the rotor and are forced inwardlyagainst the centrifugal force of the unit by the action of the sidewallsof the housing acting upon them. When each piston is in its extendedposition a passage is opened which allows gas to flow beneath the pistonin its cylinder. As the rotor turns, the pistons are forced inwardly andthe passages are closed to compress the gas which lies beneath thepistons. Each of the cylinders is sequentially open at the bottom toallow the compressed gas to escape during each revolution of the rotor.

These and other objects and features of this invention along with itsincident advantages will be better understood and appreciated from thefollowing detailed description of two embodiments thereof, selected forpurposes of illustration and shown in the accompanying drawing, inwhich:

FIG. 1 is a cross-sectional view of a compressor constructed inaccordance with this invention;

FIG. 2 is a cross-sectional view taken along the section line 2-2 ofFIG. ll;

FIG. 3 is a fragmentary detail view of a modification of the compressorshown in FIGS. 1 and 2;

FIG. 4 is an end view of a portion of the detail shown in FIG.

FIG. 5 is a fragmentary detail view of another modification of thecompressor; and

FIG. 6 is an end view of a portion of the detail shown in FIG. 5.

The compressor shown in FIGS. 1 and 2 includes a housing 10 within whichis eccentrically mounted a rotor 12. In the embodiment shown fourcylinders 14 are formed in the rotor, and each contains a piston 16which reciprocates in the cylinder as the rotor turns in the housing 10.An inlet 18 and an outlet 20 are provided in the housing.

The housing 10 includes a cylindrical peripheral wall 22 joining endwalls 24 and 26. Wall 24 is generally fiat but includes an inwardlyextending sleeve 28 on which the rotor 12 turns and through which thecompressed gas is exhausted. Bearings 30 and 32 are shown in the drawingto support the rotor, and needle bearings 34 are provided to insure itsfree rotation.

The rotor 12 includes a shaft 36 that extends out of the housing 10 andwhich may be driven by a motor or some other prime mover. Each cylinder14 is shown with and can be provided with a liner 38 to reduce frii'tionas its piston reciprocates. The liner 38 may be nylon or some similarself lubricating material. The bottom of each cylinder 14 is protheinner end 46 of each piston to a point on the sidewall 48 intermediatethe piston ends. It is evident in FIG. 2 that each slot 44 cooperateswith the inner surface of its respective cylinder 14 to form a passagefor gas contained in the housing 10 to flow into the chamber 49 in thecylinder beneath the piston 16. When the piston is in its extendedposition as is the uppermost piston 16 shown in FIGS. 1 and 2, the outerend of the slot 44 is disposed beyond the periphery 50 of the rotor 12so that gas contained in the housing may flow through the slot into thechamber 49. However, as the piston is forced inwardly to a withdrawnposition in the cylinder under the influence of the peripheral wall 22,the passage 44 ultimately closes at its outer end and the piston beginsto compress the gas below it in the chamber 48. It will be noted in FIG.2 that the inlet or outer ends of the passages 44 face in the directionof rotation of the rotor, and therefore, they form scoops to direct gasin the housing through the slots and into the chambers 49.

The outer end of each piston 16 is provided with an arcuate runner 52 ofa radius somewhat smaller than the radius of the inner surface 54 ofperipheral wall 22 of the housing. A groove on the inner surface 54 ofthe peripheral wall defines a track 56 for the runner, and thecooperation of the runners and track prevents the pistons 16 fromrotating about their own axes in the cylinder 14. The smaller radius ofthe runner 52 establishes substantially line contacts between the pistonand the wall 22 to reduce the friction area. The track 54 may be linedwith a material to further reduce friction.

From the foregoing description it is evident that as the rotor 12rotates by means of some input applied to the shaft 36, the pistons 16under the influence of centrifugal force remain in contact with the wall22 with the rails 52 within the tack 56. A spring 58 in each cylinderalso constantly urges the pistons against the wall. As each pistonpasses through region A as shown in FIG. 2, immediately after itexhausts its chamber 49 through alignment port 40 with the port 42, thepiston begins to move outwardly in its chamber until it reaches region Bwhere the outer end of the passage 44 extends beyond the periphery 50 ofthe rotor. Continued rotation of the rotor to position C maintains thepassage 44 in the open condition and gas in the housing which entersthrough the inlet 18 is allowed to enter the chamber 48 in the cylinderbeneath the piston. The piston reaches its outermost position at regionD. At region E the passage 44 closes because the inlet end slips belowthe periphery 50 of the rotor, and continued rotation of the rotordrives the piston 16 inwardly so as to compress the gas in the chamber49. When each piston reaches region F, the port 40 at the bottom of thechamber aligns itself with the passage 42, and the gas compressed in thechamber 49 is allowed to discharge through the outlet 20. Depending uponthe particular use to which the compressor is put, the outlet 20 may beconnected to a heat exchanger to reduce the gas temperature.

In FIGS. 3 and 4 a slight modification of the invention shown in FIGS. 1and 2 is illustrated. In that figure the hous ing, rotor, cylinders, andpistons are virtually the same, but a special foot 60 is carried by theend of each piston and serves as the runner. Each foot 60 is pivotallypinned to the outer end of each piston by peg 62, and the outer surface64 of the foot bears against the track 56 on the inner surface of theperipheral wall 22 of the housing. The surface 64 of the foot 60 can beprovided with a venturi-shaped recess 66 that defines a passage for airbetween the surface 64 of the foot and the surface of the track 56 inperipheral wall 22. Consequently, as the rotor turns and the foot slidesalong the track, the passage 66 acts as a scoop and creates a pressurebuild up between the track and foot which will form an air bearing forthe surface 64 of the foot. Consequently friction is markedly reduced asthe rotor turns. Except for that difference in the embodiment of FIGS. 3and 4, the compressor functions in precisely the same manner as thecompressor of the embodiment shown in FIGS. 1 and 2. The refinementshown in the embodiment of 3 and 4 reduces friction losses so as toincrease the efficiency of the compressor, and the track liner whichreduces friction further improves the operation.

In FIGS. 5 and 6, yet another modification of the invention is shown,which closely resembles the embodiment of FIGS. 3 and 4. In thismodification, the track in the peripheral wall of the housing iseliminated, and other means are used to prevent rotation of thecylinder. In the drawing cylinder 70 is shown to have a key way 72formed in its cylindrical wall, and piston 74 carries a wear pin 76 inits wall that extends into the key way. Consequently the piston isrestrained against rotary motion in the cylinder and is free to moveaxially in it.

The shoe 78 which is pivoted on the end of the cylinder by pin 80 has amuch wider surface 82 facing the peripheral wall 84 of the housing, andno track is formed to receive it. The passage 86 in the surface 82 isextended to build up pressure between the two surfaces so as to reducethe friction losses by establishing an air bearing for the foot as therotor rotates. The surfaces may be provided with a low friction materialto further achieve this goal.

From the foregoing description it will be appreciated that theembodiments of this invention shown in the drawing achieve the severalobjects set forth in the introduction. A compressor having a housingdiameter of approximately 12 inches with pistons having a stroke ofsomewhat less than 2 inches is capable of generating approximately 100p.s.i. pressure. The device is plainly inexpensive to manufacture, has avery substantial capacity because of the plurality of pistons, andprovides the high pressure without leakage problems normally found inother forms of pumps.

What I claim is:

i. A compressor comprising:

a housing having a peripheral wall,

a rotor excentrically mounted in the housing for rotation abouta fixed,central axis,

a plurality of cylinders formed in the rotor and extending to itsperiphery,

apiston mounted for reciprocal motion in each cylinder as the rotorrotates, and for rotary motion in unison with said rotor, the housingwall controlling the position of the piston as the rotor rotates,

a passage formed in the side of each piston and extending along thepiston to the inner end thereof,

each of said passages being constructed and arranged to be closed by thewall of its cylinder as its piston moves inwardly in the cylinderwhereby when said piston is in the extended position, gas in the housingbetween the peripheral wall and the rotor may move into each cylinderbelow its associated piston and when said piston moves inwardly in thecylinder said gas will be entrapped and compressed therein, and adischarge port provided at the inner end of each cylinder, each portopening as the piston in each cylinder achieves its inner position.

2. A compressor as defined in claim 1 further characterized by:

said side of said piston in which said passage is formed being exposedwhen the piston is in the extended position and being closed when thepiston is in the inner position said passage being formed in each pistonso that when said side having said passage formed therein is extended,said passage faces in the direction of rotation of said rotor.

3. A compressor as defined in claim 1 further characterized a sleeveabout which the rotor rotates,

a discharge opening provided in the sleeve and registering sequentiallywith each port once each revolution of the rotor.

4. A compressor as defined in claim 3 further characterized said sleeveserving as a conduit to convey the compressed gas discharged through theopening from the housing.

5. A compressor as defined in claim 1 further characterized an arcuaterunner formed on the end of each piston having a radius less than thatof the housing wall,

and a track in the inner surface of the wall of the housing in which therunner rides as it moves about the housing.

6. A compressor as defined in claim ll further characterized a footpivoted to the end of each piston and bearing against the inner surfaceof the housing wall.

7. A compressor as defined in claim 5 further characterized a footconnected to the piston as a runner with an air passage in the surfaceof the foot to define an air bearing for the foot on the housing wall.

8. A compressor as defined in claim 6 further characterized an airpassage in the surface of the foot to define an air bearing for the footon the housing wall.

9. A compressor as defined in claim 2 further characterized a sleeveabout which the rotor rotates,

a discharge opening provided in the sleeve and registering sequentiallywith each port once each revolution of the rotor,

said sleeve serving as a conduit to convey the compressed gas dischargedthrough the opening from the housing.

10. A compressor as defined in claim 1 further characterized by:

a keying means provided between the cylinder and piston for preventingthe piston from rotating in the cylinder as it reciprocates.

ill. A compressor as defined in claim 4 further characterized by:

a wear pin carried by each piston and riding in a key way provided ineach cylinder to prevent the pistons from rotating,

and a foot pivoted to the end of each piston and bearing against theinner surface of the housing wall.

12. A compressor as defined in claim 2 further characterized by:

means for maintaining each of said pistons in a position in which thepassage thereof faces in the direction of rotor rotation at all times.

1. A compressor comprising: a housing having a peripheral wall, a rotorexcentrically mounted in the housing for rotation about a fixed, centralaxis, a plurality of cylinders formed in the rotor and extending to itsperiphery, a piston mounted for reciprocal motion in each cylinder asthe rotor rotates, and for rotary motion in unison with said rotor, thehousing wall controlling the position of the piston as the rotorrotates, a passage formed in the side of each piston and exTending alongthe piston to the inner end thereof, each of said passages beingconstructed and arranged to be closed by the wall of its cylinder as itspiston moves inwardly in the cylinder whereby when said piston is in theextended position, gas in the housing between the peripheral wall andthe rotor may move into each cylinder below its associated piston andwhen said piston moves inwardly in the cylinder said gas will beentrapped and compressed therein, and a discharge port provided at theinner end of each cylinder, each port opening as the piston in eachcylinder achieves its inner position.
 2. A compressor as defined inclaim 1 further characterized by: said side of said piston in which saidpassage is formed being exposed when the piston is in the extendedposition and being closed when the piston is in the inner position saidpassage being formed in each piston so that when said side having saidpassage formed therein is extended, said passage faces in the directionof rotation of said rotor.
 3. A compressor as defined in claim 1 furthercharacterized by: a sleeve about which the rotor rotates, a dischargeopening provided in the sleeve and registering sequentially with eachport once each revolution of the rotor.
 4. A compressor as defined inclaim 3 further characterized by: said sleeve serving as a conduit toconvey the compressed gas discharged through the opening from thehousing.
 5. A compressor as defined in claim 1 further characterized by:an arcuate runner formed on the end of each piston having a radius lessthan that of the housing wall, and a track in the inner surface of thewall of the housing in which the runner rides as it moves about thehousing.
 6. A compressor as defined in claim 1 further characterized by:a foot pivoted to the end of each piston and bearing against the innersurface of the housing wall.
 7. A compressor as defined in claim 5further characterized by: a foot connected to the piston as a runnerwith an air passage in the surface of the foot to define an air bearingfor the foot on the housing wall.
 8. A compressor as defined in claim 6further characterized by: an air passage in the surface of the foot todefine an air bearing for the foot on the housing wall.
 9. A compressoras defined in claim 2 further characterized by: a sleeve about which therotor rotates, a discharge opening provided in the sleeve andregistering sequentially with each port once each revolution of therotor, said sleeve serving as a conduit to convey the compressed gasdischarged through the opening from the housing.
 10. A compressor asdefined in claim 1 further characterized by: a keying means providedbetween the cylinder and piston for preventing the piston from rotatingin the cylinder as it reciprocates.
 11. A compressor as defined in claim4 further characterized by: a wear pin carried by each piston and ridingin a key way provided in each cylinder to prevent the pistons fromrotating, and a foot pivoted to the end of each piston and bearingagainst the inner surface of the housing wall.
 12. A compressor asdefined in claim 2 further characterized by: means for maintaining eachof said pistons in a position in which the passage thereof faces in thedirection of rotor rotation at all times.